New study: fats in and carbs out

Scientific findings allow us to redefine our notion of a balanced diet

New study shows that eating a diet that includes 35 percent fats, including both saturated and unsaturated types, is healthier than eating a high-carb diet. (123RF)

According to the Prospective Urban Rural Epidemiology (PURE) study that looked at the differences between high-fat and low-carb diets, and the impact each has on longevity, fats may actually be a better alternative than high-carb diets for living a longer life.

The PURE study followed 135,000 people in 18 countries, which included high-, medium- and low-income nations. On average, the study followed participants for seven and a half years. The people in the study ranged in age from 35 to 70 years old.

In general, the study, which was published in The Lancet, contradicts pervious findings, instead concluding that diets higher in fat (about 35 per cent of daily energy intake), including saturated and unsaturated fat, did not increase mortality risk (a fancy way of saying they didn’t shorten people’s lifespan). However, diets high in carbohydrates did in fact, increase mortality risk. This means that people who ate a high-carb diet, on average, died sooner than people who ate a high-fat diet.

The difference in mortality rates was also significant, a roughly 20 per cent difference between the high- fat and high- carbohydrate diet groups. One of the study authors, Dr. Andrew Mente, PhD of McMaster University, says that although this may seem like a small difference, it could translate into sparing thousands to millions of lives every year by correcting dietary patterns at a population level.

Dr. Mente says that high carbohydrate diets that contribute more than 60 per cent of your energy, common in China and South Asia, may actually be harmful and are associated with a 28 per cent higher risk of premature death. This doesn’t mean, however, that following a low-carbohydrate diet is the answer. He adds that ideally, for optimal health, your daily energy intake should include a moderate carbohydrate intake of 50 to 55 per cent (which is actually the “sweet spot” according to researchers) with another 35 per cent coming from fat sources.

The debate over the ideal amounts of dietary carbohydrate and fat has raged on for decades. While conventional dietary guidelines, including our Canada’s Food Guide, recommend a moderate carbohydrate and a lower fat intake, there is also a popular movement today with the Paleolithic diet, which is essentially a low-carbohydrate and high-fat diet.

Nutritional science evolves slowly, but the data from this large study does have important implications moving forward, and researchers say it should be taken seriously. Indeed, the authors suggested that worldwide dietary guidelines should be reconsidered in light of these results.

While new scientific findings update our understanding of nutrition we should continue to focus on the basics of a healthy diet, including limiting processed food, frequently eating fresh fruit and vegetables, preparing meals at home, sharing meals with others when possible and maintaining a healthy body weight. Staying active and exercising regularly also helps us to maintain our physical fitness and general health over time.

If you have questions about carbohydrates, fats and keeping a healthy diet in general, you can ask your naturopathic doctor and they will be able to help optimize your nutrition.

Dr. Colin MacLeod ND is a naturopathic doctor practicing full-time in Upper Tantallon at MacLeod Naturopathic. His practice focuses on pain management and maintaining health through physical activity and diet. Visit him online at drcolinmacleod.com.